Tales TDS tells – The Hindu

The farm wells of Ullukurukkai village in Thimjepalli panchayat of Krishnagiri district are filled to the brim during summer months. It’s time to plant rice. Elsewhere in the district, nurseries are being raised and fields are being prepared to grow crops. But Punjab The lands (dry farmlands) of the village close to Tata Electronics Private Limited’s (TEPL) iPhone manufacturing facility have become disturbingly quiet. This shocking silence a hundred meters away is broken by the sounds of construction work. Workers are busy building a wall to separate the boundary of the TEPL facility from adjacent farmland. A regular water flow is provided from under the base of the facility’s new boundary wall to an outlet channel passing through agricultural lands.

Within a few meters of the boundary wall are large embankments consisting of rainwater harvesting structures or facility percolation ponds. In the last week of May, acres of Ullukurukkai’s agricultural land were flooded due to water reportedly overflowing from the facility’s percolation ponds. The company later told officials it was just rainwater from the ponds. Collector C. Dinesh Kumar said: “There were two cases of violation [in the last few months] from the plant and the recorded rainfall on both occasions was 5cm and 6.75cm.” However, farmers insist that what is overflowing is not just rainwater, but “chemical water” entering their fields from these ponds.

The Tamil Nadu Pollution Control Board (TNPCB) issued a show-cause notice to TEPL in May 2026. It marked the TDS (total dissolved solids) range at 1,916 milligrams per liter (mg/L) to 2,450 mg/L (versus the norm of no less than 500 ppm or no more than 1,000 ppm for percolation ponds). rainwater pond. It also marked BOD or Biological Oxygen Demand (dissolved oxygen required for the breakdown of organic matter) in the range of 12 mg/L to 78 mg/L and COD (Chemical Oxygen Demand, which indicates contamination) in the range of 48 mg/L to 160 mg/L; both values ​​significantly exceed the permissible limits below 30 mg/L. The TDS range was determined from samples collected three times at three different points between December and May.

A promising start

TEPL has chosen Nagamangalam near Hosur in 2021 to set up its iPhone component manufacturing unit. The move has been seen as a big win for Tamil Nadu’s industrial portfolio and Hosur’s manufacturing ecosystem, which is diversifying into electronics. The facility expanded with operations beginning at the Phase II facility last November. The farmers were happy to have a “good corporate company” among them. “They say Tata is a good company. We thought if they were giving jobs to so many people, they would just do it,” says Pushparaj, who is leading farmers’ protests against alleged wastewater dumping. Mr. Pushparaj repeatedly says, “Don’t we know what rainwater is? This is not rainwater.” “We grew up in this land, in this water.”

Two sources in the district administration said that one night in December 2025, the pump system of the sewage treatment plant (STP) at TEPL premises malfunctioned. Hindu. “Untreated water was being discharged into the rainwater harvesting pond. There were complaints from farmers at that time. There was a bad smell when the water was collected. But if it was commercial waste, TDS would have been much higher. It cannot be said that it was completely untreated commercial waste, but it was definitely partially treated wastewater,” said one of them.

commercial waste

Commercial waste is any liquid waste discharged from business, commercial or industrial facilities. Conventional commercial wastewater treatment systems do not correct high TDS levels. TEPL is a Zero Liquid Discharge (ZLD) unit that uses a Multiple Effect Evaporator (MEE) for wastewater treatment. Raw commercial wastewater is treated through the Reverse Osmosis (RO) process, which returns low TDS water that can be reused for horticulture. However, the discharge from the RO process (RO rejection) will have a larger TDS concentration. This RO rejection then passes through a series of evaporators (MEE) and the water is condensed for reuse. The MEE reject, which will also have high TDS values, is finally passed through the Agitated Thin Film Dryer (ATFD), which converts the high TDS rejection into powder. This technically makes TEPL a zero-discharge facility where no water or waste exits the facility.

However, the statements of two witnesses at the facility reflect the farmers’ claims. They note that the ZLD environmental mandate can only exist on paper. According to them, commercial wastewater routinely bypasses the ETP and enters catch basins along with the STP discharge. When production is high and wastewater output exceeds ETP capacity, commercial wastewater from the anodizing process will be stored in tanks and discharged from the plant by two people at night and during rain. “Incoming production wastewater [trade effluent] With a pH level of 0-1, it will be highly acidic. Before the wastewater is fed into the treatment line, its pH value must be chemically raised to reach a neutral level. However, this is chemical intensive, expensive and time consuming for high volumes. ETP’s capacity was initially only 60 kilolitres [60,000 litres]“But the plant can sometimes produce up to 100 kilolitres of commercial waste and the excess will find its way into the sewers,” said a source working at ETP. Sometimes how often? “Two or three times a week, but depending on production output,” he said. “The TDS of commercial waste will be very high – 6,000, even 10,000. But when connected to the STP line, which has a higher volume but much less TDS, the final TDS numbers drop and stabilize against the permissible limits. The valves will open in the rain with the TDS diluted.”

“We use caustic soda to raise the pH value. The production team will send an e-mail the next day informing us of the incoming wastewater. We either collect the wastewater in the tanks (waiting for treatment) by discharging it into the drain, or we ask them to stop production. Production cannot be stopped, or it can only be stopped for a day or two. In other words, the wastewater will be sent to the drain and STP water will be poured on it.” What about metal residue? “There will be no precipitated metal residue, but the TDS of commercial effluent will appear high and this is fixed when mixed with STP water,” the source said.

Operation Consent

On November 24, 2025, TNPCB issued Operational Consent approval for the expansion of TEPL Phase I. The order states that 3.74 crore metal cases will be produced annually for iPhones. The instruction also mentions the disposal points of sewage discharge (for gardening, toilet flushes and cooling tower) and commercial wastewater discharge (recycling process and conversion into salts); None of this will be released into percolation ponds for groundwater recharge. On December 8, 2025, Mr. Pushparaj petitioned TEPL on behalf of the farmers for “failure to act on their earlier complaints regarding odor and disposal of ‘chemical effluents’ into percolation ponds.” The petition stated that this situation had been going on for “three months” (before December) but no action had been taken regarding their complaints.

This February, he said, his coriander fields, among others, faced similar flooding from the factory’s ponds and showed colorful printouts of the submerged crop to the district administration. “I was asked to be patient as the treatment plant will be ready soon,” says Mr. Pushparaj. “Production in Phase II started a year ago, but ETP was commissioned only four months ago,” the source said.

Hindu submitted questions to TEPL for comment on these witness statements from within the facility, but no official communication was received in response. However, TEPL last week issued a statement saying the TDS figures were within permissible limits and left TNPCB’s review. TNPCB did not respond to calls to confirm the development.

Adequate treatment facilities

Collector Mr. Kumar rejected the residents’ submissions and said that the plant was a ZLD plant and the adequacy of treatment facilities was ensured before approval was given. Based on inspections, verification of records, and analysis of samples, no evidence was found that industrial waste was bypassed from the treatment system or mixed with sewage for dilution and discharged into percolation ponds. “Additionally, samples collected from ponds and nearby wells were analyzed and the results did not indicate any contamination attributable to the discharge of industrial waste from the unit,” he said. Another official also alleged that Mr. Pushparaj was working with an agenda of seeking financial compensation from the company.

But the fields tell a different story and Mr Pushparaj is not the only one affected. Nagalakshmi, who owns only three-quarters of an acre of land, had harvested 300 sacks of cucumber last summer and 500 sacks the year before. This week, on day 25, he stood next to a crop of cucumbers that were only ankle high when they should have reached his waist. Ms. Nagalakshmi had created a dam to prevent “dirty water” from entering her field. “That ‘dirty water’ was here until yesterday, it had just receded. That’s why the soil is wet.” The story of low yields echoes across the region. Horticultural crops are grown here all year round, except for the small window where paddy is planted at this time of the year. Farmers grow cauliflower, beans, cucumber, ragi and flowers through drip irrigation. They suspect wastewater is leaking into the wells because the plant channels its wastewater into rainwater infiltration ponds designed to facilitate soil infiltration. “Water levels are low in other villages. Here our wells are overflowing and sewage ponds are leaking,” says Ramesh. “The water in our wells tasted like ‘soft coconut’ water,” says village head Krishnan. “Until a year and a half ago, people working in the fields drank water from these wells, but now farmers carry their own water because the well water is spoiled and creates a bad smell.”

Hindu He collected two water samples: one from the outlet canal, which was also the first point of discharged water flowing continuously under the plinth of the plant’s newly built boundary wall, and the other from the adjacent farm well. TDS values ​​were 1,789 and 1,539, respectively (safe limit 1,000 ppm), while pH was 7.88 and 6.81, respectively (acceptable range 5.5 to 6.5). Mr. Pushparaj’s water sample in April had a TDS of 1.721 and a pH of 8.09. “This is not conducive to agriculture at all. Farmers’ skin will also be irritated,” says the former Joint Director of Horticulure in Hosur, adding that high TDS will affect drip lines and borewells. “They can switch to oilseeds, but eventually they will have to abandon their land because that will suck out all the nutrients.”

When asked about compensation for losses suffered by farmers, the Collector said that the company has been asked to conduct continuous TDS monitoring. It is also necessary to ensure that no puddles occur during periods of heavy rain. “We will tell them to use HTPE if necessary [high-density polyethylene] “As requested by farmers, rainwater collection ponds will be laid to prevent further mixing with groundwater,” he added.